linux-rdma.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Olga Kornievskaia <aglo@umich.edu>
To: linux-rdma <linux-rdma@vger.kernel.org>
Subject: Help understand use of MAC address resolution in RDMA
Date: Thu, 5 Aug 2021 10:38:42 -0400	[thread overview]
Message-ID: <CAN-5tyGiuTXBy2pcSd6PT3_Bdxx6H8QWzXaurSooMz7uhU2rrw@mail.gmail.com> (raw)

Hi folks,

Can somebody help me understand how RoCE (this is probably RDMA core
and not specific to RoCE but I'm not sure) manages destination MAC
addresses for its connection?

Specifically the problem being observed is a server initiates an RDMA
CM disconnect (client replies), client tries to reconnect. Server
sends an ARP advertising a different MAC for the IP that the RDMA
connection was using. RDMA code keeps sending the RDMA CM connect
message to the old MAC for a certains period of time (90-100sec) then
it finally sends it to the new MAC address.

Question: how does the core RDMA layer manage the MAC address for the
connection. Why does it seem like it ignores the ARP updates?

Thank you.

             reply	other threads:[~2021-08-05 14:39 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-05 14:38 Olga Kornievskaia [this message]
2021-08-06  1:44 ` Help understand use of MAC address resolution in RDMA Jason Gunthorpe
2021-08-06  2:05   ` Olga Kornievskaia

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAN-5tyGiuTXBy2pcSd6PT3_Bdxx6H8QWzXaurSooMz7uhU2rrw@mail.gmail.com \
    --to=aglo@umich.edu \
    --cc=linux-rdma@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).